1. Field of the Invention
This invention relates to electrical cable clamps, and more particularly relates to a clamp which is adapted to mechanically retain a plurality of cables in fixed disposition with each other and simultaneously couple in strain relieved configuration the conductive tubular shields of such cables to a common electrical ground.
2. Description of the Prior Art
In the electrical field, especially in telephone communication and transmission, it is frequently desirable to clamp a selective number of cables from a cable bundle in fixed disposition with each other preliminary to directing certain of the clamped cables to a certain location or zone. Such cables usually include a plurality of individual wire conductors which are encapsulated within an outer covering encased about a tubular extruded or braided sheath, preferably copper, which acts as an electrical shield for transmissions through the wire conductors themselves. The encircling conductive shield of these cables are usually coupled to a common electrical ground by way of a clamp compressively contacting the metallic sheath from which a portion of the outer cover has been skinned or stripped. The cables themselves are of various diameters depending upon the number and gauge of the individual wire conductors.
In the past, it has been the usual practice to provide a cable clamp wherein only a single cable was embraced by each jaw of a stacked array so that the cable in each set of jaws was retained in spaced parallel disposition with respect to the other clamped cable elements. Such prior cable clamps tended to distort the cables excessively and required excessive pressures in order to prevent loosening. In addition to these drawbacks, such clamps were likely to be expensive owing to the intricate nature of the cast or machine parts from which the clamp was assembled. Moreover, the use of a clamping arrangement in which only a single cable was retained within one set of jaws of a stacked set of such jaws necessarily increased the overall size of the cable clamp. Added to the mass of metal embodied within the clamp with consequent augmentation in cost and detracted from the ability of the clamp to function with uniform pressure upon the various cables being integrated. Yet another difficulty experienced with prior cable clamps was the problem of coupling them to a housing or bracket while at the same time threading or nesting of the individual cables within the jaws, such difficulty resulting from the unstable nature of the coupling mechanism which could not restrain rotational movement or twisting of the clamp either prior to or during the clamping procedure.
An example of one cable clamp which has attempted to overcome the problems described above is shown in U.S. Pat. No. 4,136,423 (hereinafter the '423 patent) which issued on Jan. 30, 1979 in the name of Maurice Sterling. The clamp shown therein includes a body portion and a jaw member. The cable is trapped between a flat surface and two edges of the body portion and the jaw member. Trapping the cable against the edges of the body portion may give rise to certain undesirable results in that only a small surface area of the body portion is in contact with the cable.